The present nonprovisional application claims priority under 35 USC 119 to Japanese Patent Application No. 2002-182573 filed on Jun. 24, 2002 the entire contents thereof is hereby incorporated by reference.
1. Field of the Invention
The present invention relates to a wing structure in an airplane in which a plurality of ribs extending in a cord direction are coupled between a front first spar and a rear second spar extending in a span direction.
2. Description of the Related Art
A main wing of an airplane has a structure in which a plurality of ribs extending in a cord direction are fixed at predetermined intervals to a plurality of spars extending in a span direction, and surfaces and backs of the spars and the ribs are covered with a skin for the airplane. The positioning of the ribs in the span direction and the cord direction relative to the spars has been carried out using an expensive and special assembling jig. Such assembling jig is poor in general-purpose properties, and hence is required to be prepared for each wing type. This causes an increase in equipment cost for the assembling jig.
Therefore, if a rib-positioning function is eliminated from the assembling jig for the wing of the airplane, the cost of the assembling jig can be remarkably reduced.
Accordingly, it is an object of the present invention to enable an accurate assembling of a wing of an airplane by using an inexpensive assembling jig having no rib-assembling function.
To achieve the above object, according to a first feature of the present invention, there is provided a wing structure for an airplane in which a plurality of ribs extending in a cord direction are coupled between a front first spar and a rear second spar extending in a span direction, wherein each of the first and second spars is a C-shape or an I-shape in section, having a web and a pair of flanges connected to opposite ends of the web, and having a reinforcing partition wall connected to the web and the flanges. The ribs are positioned in the span direction by coupling front portions of the ribs to the reinforcing partition wall of the first spar and coupling rear portions of the ribs to the reinforcing partition wall to the second spar.
With the above arrangement, each of the first and second spars of the C-shape or I-shape in section has the web, the pair of flanges and the reinforcing partition wall connected to the web and the flanges. Therefore, the ribs can be positioned in the span direction by coupling the front portions of the ribs to the reinforcing partition walls of the first spar and coupling the rear portions of the ribs to the reinforcing partition walls of the second spar. The positioning of the ribs in the span direction is carried out utilizing the reinforcing partition walls mounted to enhance the rigidity of the first and second spars. Hence, a rib-positioning function can be omitted from an assembling jig, and an accurate assembling of the wing can be ensured without use of a special positioning member to reduce the cost.
According to a second feature of the present invention, in addition to the arrangement of the first feature, the ribs are positioned in the cord direction by bringing one of the front and rear ends of the ribs into abutment against the web of one of the first and second spars.
With the above arrangement, the ribs can be positioned in the cord direction, without the provision of a special positioning member, by bringing one of the front and rear ends of the ribs into abutment against the web of one of the first and second spars, thereby precisely assembling the wing.
According to a third feature of the present invention, in addition to the arrangement of the second feature, in order to bring one of the front and rear ends of said ribs into abutment against said web of one of said first and second spars, a shim is provided in a gap defined between the flange of the other of the first and second spars and each of the ribs.
With the above arrangement, the shim is provided in the gap defined between the flange of the other of the first and second spars and each of the ribs. Hence, the one of the front and rear ends of the ribs can be brought reliably into abutment against the web of one of the first and second spars, leading to a further enhancement in accuracy of positioning of the ribs in the cord direction.
In the embodiment described, a front spar 11 corresponds to the first spar of the present invention. An intermediate spar 12 corresponds to the second spar and a projection 24b corresponds to the shim of the present invention.
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.